EWSR1 and Ewing sarcoma: Supporting a neuroectodermal lineage is that ectopic EWS/FLI expression is tolerated in NCSC (von Levetzow et al., 2011) and gene expression profiles and cell surface antigens in Ewing sarcoma are commonly expressed in neural tissues and NCSCs (Lipinski et al., 1987; Staege et al., 2004; von Levetzow et al., 2011).